<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
<style>
    p::before{
        content: '';
        display: block;
        width: 10px;
        height: 10px;
        background-color: blue;
    }
    p:hover{
        background-color: red;
    }
</style>
    <p>1111111</p>
</body>
</html>